Noctilucent Clouds seen at record low latitudes

For the past several nights, Noctilucent Clouds, extremely high altitude weather phenomenon typically only seen above latitudes of 50 deg, have been seen as far south as San Francisco (38 deg). spaceweathergallery.com has many images uploaded by professionals and amateur alike of this amazing phenomenon. I got my first chance to see them last night, they were so bright the farm was bathed in blue light and I could easily capture them freestanding at ISO 6400 using 1/15s exposure:

http://spaceweathergallery.com/indiv_upload.php?upload_id=15...

If you're above ~40 deg latitude, step outside tonight around 30 minutes after sunset and look northward and look for the telltale high blue electric streams.